l-Cysteine-Terminated Triangular Silver Nanoplates/MXene Nanosheets are Used as Electrochemical Biosensors for Efficiently Detecting 5-Hydroxytryptamine

Abstract

5-Hydroxytryptamine (5-HT) is an important neurotransmitter, and its content in the human body is of great significance to human health. In this study, an L-cysteine-terminated triangular silver nanoplate loaded on a MXene (twodimensional transition metal carbide or nitride) (Tri-AgNP/L-Cys/MXene) electrochemical sensor was used to detect 5-HT. As an electrically active amino acid with a sulfhydryl group, L-cysteine (L-Cys) forms a more stable Ag−S bond with silver nanoparticles, which can selectively substitute trisodium citrate (TSC) in TSCcapped triangular silver nanoplates (Tri-Ag-NP/TSC). Due to the good conductivity, biocompatibility, and large surface area, MXenes provide a good platform for loading Tri-AgNP/L-Cys. Under optimized conditions, the concentration range for detecting 5-HT with the sensor is 0.5−150 μM, and the limit of detection (LOD) is 0.08 μM (S/N = 3). For detecting 5-HT in actual serum samples, the sensor also showed a good recovery rate (95.38−102.3%), and the relative standard deviation was 2.2−3.4%.

Robust Electrochemical Sensors for Detection of Isoprenaline Using Hexagonal Co3O4 Nanoplates Embedded in Few-Layer Ti3C2Tx Nanosheets

“…The spectra do not contain any Ti–O bond near 458 eV, confirming MXene as pure Ti 3 C 2 T x . ,, The C 1s spectra for Co 3 O 4 –MX contained typical binding energies of C–T, C–C, −C–O, and −COOH near 282.5, 284.7, 286.15, and 288.1 eV, respectively. The O 1s spectra further confirmed Ti–O–Ti bonds at 530.2 eV with other smaller binding energies for −Ti–OH and −C–O binding energies justifying the un-oxidized form of Ti 3 C 2 T x MXenes . The XPS analysis of the Co 3 O 4 –MX reveals that the composite formation has been successfully attained without compromising the inherent properties of Ti 3 C 2 T x and Co 3 O 4 -HX.…”

“…OH and −C−O binding energies justifying the unoxidized form of Ti 3 C 2 T x MXenes 12. The XPS analysis of the Co 3 O 4 −MX reveals that the composite formation has been successfully attained without compromising the inherent properties of Ti 3 C 2 T x and Co 3 O 4 -HX.…”

“…Furthermore, these approaches need a well-maintained infrastructure and are unsuitable for field applications. Recently, electrochemical techniques, particularly modified-electrode-based sensors, have gained immense attention in the analytical quantification of pharmaceuticals. ,, The high sensitivity of the modified electrodes, reliability, and, more importantly, possibility of miniaturization have opened new horizons to detecting pharmaceuticals in formulations and biological and environmental media for trace samples with a minimum pre-treatment requirement. − Furthermore, recent advancements in electrode engineering, along with highly conducting nanomaterials such as MXenes, have allowed the developed sensors to deliver competitive benefits including low detection limits, wider detection ranges, and shorter analysis time. , …”

Construction of Ag nanowire@Au nanoparticle nano nests with densely stacked small gaps for actively trapping molecules to realize diversity SERS detection

“…5-HT is an important neurotransmitter, and its content is of great significance to human health. 34 Therefore, 5-HT may serve as a new therapeutic target to reduce symp-toms such as dermatitis caused by mosquito bites. The promising specificity of this method provide a new approach for further in situ SERS biosensing fields.…”

Preparation of tannic acid and l-cysteine functionalized magnetic composites for synergistic enrichment of N-glycopeptides followed by mass spectrometric analysis

“…[46][47][48] and further introduction of L-Cys through the Ag-S bond. 49,50 Overall, this research not only promotes the development of N-glycopeptide enrichment with synergistic hydrophilic materials, but also is an attempt to enrich N-glycopeptides with TA, broadening its application scope in the eld of biological separation.…”